<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
  </head>
  <body>
    <script>
    var newarr = [
  { num: 1, val: 'ceshi', flag: 'aa' },
  { num: 2, val: 'ceshi2', flag: 
  'aa2'
  }
]

const t = newarr.map(item => item)
console.log(t)
console.log(newarr.filter(item => item.num===2 ))
let num = '你好'
if(!num) {
return false
}
const kko = 900
console.log(kko)
  </script>
  </body>
</html>